I needed to review in the most efficient way possible. I had a sheet of review problems ready. I wanted each student to focus on his/her weakness because there wasn't time to do them all in class.
I ended up instructing the students to skim the review problems and start on the hardest problems. I literally told them to find the problem that scares them the most and start with that. Better to do those in class where they could ask questions and save the easier ones to finish at home. And, since I knew those instructions would result in 10 hands raised simultaneously, I also used my planning period to write out the solutions on post-it notes and put them on the board like this:
Students could raise their hand to get help from me. Or, they could discuss a problem with their partner. Or, they could go grab the sticky note for the problem they were working on. I put the number of the problem under each post-it, so that students could tell at a glance which notes were already in use.
The whole day was less thorough and more chaotic than what I would normally plan. But my goal was accomplished: Everyone left the room having completed the problems they viewed as most challenging. All in under 35 minutes.
And they are going to go home tonight and take a second look at every problem they completed with assistance and try it again without assistance. Okay, probably not, but I did tell them to do that.